In recent years, small electrical and electronic products have been produced in more varieties and in smaller quantities, and the product life cycles of the products have been shortening. Production lines for producing the products tend to be frequently reconfigured to suit products to be produced. In a transition to another product on such a production line, changes to the production line require time, and a specialized jig needs to be produced. If products are not to be produced in somewhat large quantities, manual cell production is often adopted instead of an automated production line. However, even in this case, automation of a production line is needed to, e.g., stabilize the quality of products and deal with a rapid increase in production.
For this reason, general-use assembling apparatuses have recently attracted attention (see Japanese Patent Application Laid-Open No. 2009-148869). A production system including such assembling apparatuses uses a robot arm to machine and convey a workpiece serving as an object to be machined, and the plurality of assembling apparatuses can be rearranged according to each production plan to construct a new production system. In the event of a rapid increase in production, a general-use assembling apparatus can be removed from another production system whose production capacity is to be reduced and can be used in a new production system.
Important factors in fabricating the above-described assembling apparatuses include a reduction in the footprint of each assembling apparatus. Even a general-use assembling apparatus has few advantages if the assembling apparatus has a large footprint relative to a human assembly line. In contrast, in each assembling apparatus described in Japanese Patent Application Laid-Open No. 2009-148869, a robot arm with not less than six degrees of freedom is fixed to a side wall of a chassis, and a general-use camera with a wide field of view is fixed to a ceiling portion of the chassis. The installation space is minimized by canceling out a tolerance between the position of each robot arm and the position of a workpiece using a result of imaging by the camera and changing an operating program so as to perform various pieces of work. With this configuration, the assembling apparatus is available in many production sites.
However, since a robot arm is fixed to a side wall of a chassis in a conventional assembling apparatus, the chassis is unstable to swings of the robot arm. Vibrations different from vibrations to which a workpiece is subjected due to swings of the robot arm are applied to the camera provided at the ceiling portion, and the vibrations reduce the detection accuracy of the camera. Methods for avoiding the problem include a process of performing imaging by the camera after swings of the camera converge. In this method, a ceiling surface needs to be located at a somewhat large height for securing a workspace for the robot arm. This lengthens the swing period of the chassis. Once the chassis starts vibrating, it takes a long time for swings of the camera to converge. Accordingly, waiting until swings of the camera converge leads to an increase in a period of time during which the work of the robot arm is stopped, which causes a reduction in the pace of production.
Under the circumstances, it is an object of the present invention to provide an assembling apparatus capable of reducing vibrations of a camera which images the working area of a robot arm and a production system using the assembling apparatus.